Answer:
The correct answer is A. active transport
Explanation:
There are two types of transport which helps in the transport of molecules across the cell membrane. These are active transport and passive transport. In passive transport, the molecules move across the membrane without any energy expenditure and down their concentration gradient.
In active transport, molecules move against their concentration gradient with the help of ATP so in active transport, molecules can be present in high concentration outside or inside the cell.
Sodium is an ion that moves by active transport in and out of the cell with the help of sodium-potassium pump so it's so the correct answer is A.
Answer:
The nucleus at the central part of the cheek cell contains DNA. When a drop of methylene blue is introduced, the nucleus is stained, which makes it stand out and be clearly seen under the microscope.
Copied
Osmiosis is the structure that stops water loss in leaves
Explanation:
Tahukah kamu, mengapa motor berhenti di depan lampu merah?
karena motornya direm. Coba kalau nggak direm bisa bahaya tuh.
Tebak binatang apa yang jago renang?
Bebek. Kalau ikan bukan renang tapi menyelam
Kenapa di rel kereta api ditaruh batu?
Soalnya kalau ditaruh duit nanti pada diambil.
Crossing over occurs at the four-strand stage when two homologous chromosomes, each consisting of a pair of sister chromatids, are paired. Each crossover involves just two of the four strands and generates two recombinant strands.
Hope this helps!